{"title":"Effect of impinging jet on rapid cooling of a miniature Joule-Thomson cryocooler: Experimental study of operating conditions","authors":"","doi":"10.1016/j.ijrefrig.2024.06.017","DOIUrl":null,"url":null,"abstract":"<div><p>A miniature open-cycle Joule-Thomson (J-T) cryocooler possesses excellent potential for rapid cooling from ambient temperature to about 100 K within seconds. In this rapid cooling process, the interplay of the heat transfer process between the cryogenic fluid and the cold plate plays a crucial role, in addition to the J-T effect and the energy recovery within the heat exchanger of the cryocooler. The phase state of the impinging jet is determined by the jet temperature and has different heat transfer mechanism. To investigate this impinging jet behavior separately, an experimental system for the rapid cooling J-T cryocooler was set up and the jet temperature was measured besides other important parameters. The operating conditions, including the cylinder pressure, cylinder volume, ambient temperature, and the refrigerant, were studied orthogonal. It was observed that argon, compared to nitrogen, can be more rapidly throttled into its two-phase region within a second. However, nitrogen will perform better than argon in terms of cool-down time. This is attributed to the temperature difference between the jet and the cold plate, which significantly influences the boiling mode of the two-phase jet, and in turn affects the cryocooler's cooling rate. Nevertheless, due to the smaller heat transfer intensity of single-phase jet, the cool-down time of nitrogen deteriorates quickly at high ambient temperatures. Experimental results also revealed that the cooling rate of the cryocooler still can be enhanced even if cylinder pressure beyond its saturation curve, caused by the dynamic cooling process and the pressure drop within the finned tube.</p></div>","PeriodicalId":14274,"journal":{"name":"International Journal of Refrigeration-revue Internationale Du Froid","volume":null,"pages":null},"PeriodicalIF":3.5000,"publicationDate":"2024-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Refrigeration-revue Internationale Du Froid","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0140700724002196","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
Abstract
A miniature open-cycle Joule-Thomson (J-T) cryocooler possesses excellent potential for rapid cooling from ambient temperature to about 100 K within seconds. In this rapid cooling process, the interplay of the heat transfer process between the cryogenic fluid and the cold plate plays a crucial role, in addition to the J-T effect and the energy recovery within the heat exchanger of the cryocooler. The phase state of the impinging jet is determined by the jet temperature and has different heat transfer mechanism. To investigate this impinging jet behavior separately, an experimental system for the rapid cooling J-T cryocooler was set up and the jet temperature was measured besides other important parameters. The operating conditions, including the cylinder pressure, cylinder volume, ambient temperature, and the refrigerant, were studied orthogonal. It was observed that argon, compared to nitrogen, can be more rapidly throttled into its two-phase region within a second. However, nitrogen will perform better than argon in terms of cool-down time. This is attributed to the temperature difference between the jet and the cold plate, which significantly influences the boiling mode of the two-phase jet, and in turn affects the cryocooler's cooling rate. Nevertheless, due to the smaller heat transfer intensity of single-phase jet, the cool-down time of nitrogen deteriorates quickly at high ambient temperatures. Experimental results also revealed that the cooling rate of the cryocooler still can be enhanced even if cylinder pressure beyond its saturation curve, caused by the dynamic cooling process and the pressure drop within the finned tube.
期刊介绍:
The International Journal of Refrigeration is published for the International Institute of Refrigeration (IIR) by Elsevier. It is essential reading for all those wishing to keep abreast of research and industrial news in refrigeration, air conditioning and associated fields. This is particularly important in these times of rapid introduction of alternative refrigerants and the emergence of new technology. The journal has published special issues on alternative refrigerants and novel topics in the field of boiling, condensation, heat pumps, food refrigeration, carbon dioxide, ammonia, hydrocarbons, magnetic refrigeration at room temperature, sorptive cooling, phase change materials and slurries, ejector technology, compressors, and solar cooling.
As well as original research papers the International Journal of Refrigeration also includes review articles, papers presented at IIR conferences, short reports and letters describing preliminary results and experimental details, and letters to the Editor on recent areas of discussion and controversy. Other features include forthcoming events, conference reports and book reviews.
Papers are published in either English or French with the IIR news section in both languages.